Estimation of 3D vegetation structure from waveform and discrete return airborne laser scanning data

This study presents and compares new methods to describe the 3D canopy structure with Airborne Laser Scanning (ALS) waveform data as well as ALS point data. The ALS waveform data were analyzed in three different ways; by summing the intensity of the waveforms in height intervals (a); by first normalizing the waveforms with an algorithm based on Beer-Lambert law to compensate for the shielding effect of higher vegetation layers on reflection from lower layers and then summing the intensity (b); and by deriving points from the waveforms (c). As a comparison, conventional, discrete return ALS point data from the laser scanning system were also analyzed (d). The study area was located in hemi-boreal, spruce dominated forest in the southwest of Sweden (Lat. 58° N, Long. 13° E). The vegetation volume profile was defined as the volume of all tree crowns and shrubs in 1 dm height intervals in a field plot and the total vegetation volume as the sum of the vegetation volume profile in the field plot. The total vegetation volume was estimated for 68 field plots with 12 m radius from the proportion between the amount of ALS reflections from the vegetation and the total amount of ALS reflections based on Beer-Lambert law. ALS profiles were derived from the distribution of the ALS data above the ground in 1 dm height intervals. The ALS profiles were rescaled using the estimated total vegetation volume to derive the amount of vegetation at different heights above the ground. The root mean square error (RMSE) for cross validated regression estimates of the total vegetation volume was 31.9% for ALS waveform data (a), 27.6% for normalized waveform data (b), 29.1% for point data derived from the ALS waveforms (c), and 36.5% for ALS point data from the laser scanning system (d). The correspondence between the estimated vegetation volume profiles was also best for the normalized waveform data and the point data derived from the ALS waveforms and worst for ALS point data from the laser scanning system as demonstrated by the Reynolds error index. The results suggest that ALS waveform data describe the volumetric aspects of vertical vegetation structure somewhat more accurately than ALS point data from the laser scanning system and that compensation for the shielding effect of higher vegetation layers is useful. The new methods for estimation of vegetation volume profiles from ALS data could be used in the future to derive 3D models of the vegetation structure in large areas

Soft nanostructuring of YBCO Josephson Junctions by phase separation

We have developed a new method to fabricate biepitaxial YBa2Cu3O(7-x) (YBCO) Josephson junctions at the nanoscale, allowing junctions widths down to 100 nm and simultaneously avoiding the typical damage in grain boundary interfaces due to conventional patterning procedures. By using the competition between the superconducting YBCO and the insulating Y2BaCuO5 phases during film growth, we formed nanometer sized grain boundary junctions in the insulating Y2BaCuO5 matrix as confirmed by high resolution transmission electron microscopy. Electrical transport measurements give clear indications that we are close to probing the intrinsic properties of the grain boundaries.Comment: 16 pages, 6 figure

Динамика физического развития и физической подготовленности студентов ВГМУ основного медицинского отделения в процессе обучения на 1-4 курсах

GOALS OF WORK: Staff members in palliative home care play an important role in supporting bereaved family members. The aim of this study was to explore staff members' perspectives on providing such support. MATERIAL AND METHODS: Staff members in six units responded (n = 120; response rate 58%) to a postal questionnaire with Likert-type and open-ended questions. The responses were analyzed using statistics and manifest content analysis. MAIN RESULTS: None of the respondents stated that bereavement follow-up was "most often difficult," 23% "most often rather difficult," 52.5% "most often rather easy," and 12.5% "most often easy." Apart from a tendency for age to be linked to perceived difficulty, there were no apparent patterns. Bereavement follow-up was a positive opportunity to support the family member's coping with their bereavement and to get feedback on the palliative care provided. Critical aspects concerned the question of whose needs actually were being met at bereavement follow-up, i.e., the staff members' needs for getting feedback on the care provided versus the risk of burdening the family members' by reminding them of the deceased's dying trajectory. Aspects that negatively influenced the staff members' experiences were complex and related, e.g., to the family member's dissatisfaction with the care provided, to the staff member's perceived lack of competence, and to the staff member's relationship to the family member. CONCLUSIONS: Bereavement follow-up was perceived as a rewarding conclusion to the relationship with the family member. The findings suggest that meaning-based coping might be an appropriate framework when understanding staff members' experiences with providing bereavement follow-up.The original publication is available at www.springerlink.com: Anna Milberg, Gudrun Appelquist, Eva Hagelin, Maria Jakobsson, Eva-Carin Olsson, Maria Olsson and Maria Friedrichsen, "A rewarding conclusion of the relationship": staff members' perspectives on providing bereavement follow-up, 2011, Supportive Care in Cancer, (19), 1, 37-48. http://dx.doi.org/10.1007/s00520-009-0786-0 Copyright: Springer International http://www.springerlink.com

Does the Exploratorium Evoke Emotion?

In this paper we describe a virtual reality (VR) environment, the Exploratorium, which was developed within the EU funded project EMMA (http://www.emma.upv.es/), and was designed to encourage self-directed exploration of emotions in learning how to handle different moods. It consists of three levels, each designed to generate a different mood. One main idea behind the Exploratorium is to evoke different kinds of emotions in different areas, and when the user explores and experiences these areas she recognizes, becomes aware of and gets in touch with her own feelings and emotions. The article starts by describing the theoretical background behind the environment, followed by a description of the environment (The Exploratorium) and the interaction device (The Body Joystick). We also report a first pilot study of the emotional aspects of the environment and the interaction device. The article ends with conclusions from the pilot study and a discussion about future work with the Exploratorium

Field-Dependent Heat Dissipation of Carbon Nanotube Electric Currents

We study heat dissipation of a multi-wall carbon nanotube (MWCNT) device fabricated from two crossed nanotubes on a SiNx substrate under the influence of a constant (DC) electric bias. By monitoring the temperature of the substrate, we observe negligible Joule heating within the nanotube lattice itself and instead heating occurs in the insulating substrate directly via a remote-scattering heating effect. Using finite element analysis, we estimate a remote heating parameter, beta, as the ratio of the power dissipated directly in the substrate to the total power applied. The extracted parameters show two distinct bias ranges; a low bias regime where about 85% of the power is dissipated directly into the substrate and a high bias regime where beta decreases, indicating the onset of traditional Joule heating within the nanotube. Analysis shows that this reduction is consistent with enhanced scattering of charge carriers by optical phonons within the nanotube. The results provide insights into heat dissipation mechanisms of Joule heated nanotube devices that are more complex than a simple heat dissipation mechanism dominated by acoustic phonons, which opens new possibilities for engineering nanoelectronics with improved thermal management

Classification of tree species classes in a hemi-boreal forest from multispectral airborne laser scanning data using a mini raster cell method

Classification of tree species or species classes is still a challenge for remote sensing-based forest inventory. Operational use of Airborne Laser Scanning (ALS) data for prediction of forest variables has this far been dominated by area-based methods where laser scanning data have been used for estimation of forest variables within raster cells. Classification of tree species has however not been achieved with sufficient accuracy with area-based methods using only ALS data. Furthermore, analysis of tree species at the level of raster cells with typical size of 15 m ? 15 m is not ideal in the case of mixed species stands. Most ALS systems for terrestrial mapping use only one wavelength of light. New multispectral ALS systems for terrestrial mapping have recently become operational, such as the Optech Titan system with wavelengths 1550 nm, 1064 nm, and 532 nm. This study presents an alternative type of area-based method for classification of tree species classes where multispectral ALS data are used in combination with small raster cells. In this ?mini raster cell method? features for classification are derived from the intensity of the different wavelengths in small raster cells using a moving window average approach to allow for a heterogeneous tree species composition. The most common tree species in the Nordic countries are Pinus sylvestris and Picea abies, constituting about 80% of the growing stock volume. The remaining 20% consists of several deciduous species, mainly Betula pendula and Betula pubescens, and often grow in mixed forest stands. Classification was done for pine (Pinus sylvestris), spruce (Picea abies), deciduous species and mixed species in middle-aged and mature stands in a study area located in hemi-boreal forest in the southwest of Sweden (N 58?27?, E 13?39?). The results were validated at plot level with the tree species composition defined as proportion of basal area of the tree species classes. The mini raster cell classification method was slightly more accurate (75% overall accuracy) than classification with a plot level area-based method (68% overall accuracy). The explanation is most likely that the mini raster cell method is successful at classifying homogenous patches of tree species classes within a field plot, while classification based on plot level analysis requires one or several heterogeneous classes of mixed species forest. The mini raster cell method also results in a high-resolution tree species map. The small raster cells can be aggregated to estimate tree species composition for arbitrary areas, for example forest stands or area units corresponding to field plots

La creatividad enjaulada en la traducción: una perspectiva neoinstitucional sobre la comunicación de crisis

Crisis communication research has primarily focused on universal models guiding managers of various organisations in times of crisis. Even though this is about to change, a tendency remains for research in the field to overlook the impact of structural conditions on organisation’s crisis communication. In order to add to the emergent discussion on new theoretical and empirical venues within the field of crisis communication, this paper proposes a framework based on new institutional theory for analysing crisis communication practices as a societal phenomenon. New institutionalism is advocated due to its ability to shift the focus from agency to structure and in doing so emphasise the social preconditions for organisational activities. In line with this, this conceptual paper discusses crisis communication as an institution, i.e., as a set of more or less conscious ideas about formats (the organisational structures developed for crisis communication work), contents (the content of organisations’ communication in times of crisis) and contexts (the situations during which organisations are expected to perform crisis communication). Moreover, we discuss how these ideas become translated (i.e., modified) as they travel (i.e., become legitimate, popular and get widely spread) across organisational and institutional contexts. In order to illustrate the framework described above, the Swedish authorities’ communication in connection to the A/H1N1 outbreak is used as a case study

Experimentally Calibrated Kinetic Monte Carlo Model Reproduces Organic Solar Cell Current-Voltage Curve

Kinetic Monte Carlo (KMC) simulations are a powerful tool to study the dynamics of charge carriers in organic photovoltaics. However, the key characteristic of any photovoltaic device, its current-voltage ($J$-$V$) curve under solar illumination, has proven challenging to simulate using KMC. The main challenges arise from the presence of injecting contacts and the importance of charge recombination when the internal electric field is low, i.e., close to open-circuit conditions. In this work, an experimentally calibrated KMC model is presented that can fully predict the $J$-$V$ curve of a disordered organic solar cell. It is shown that it is crucial to make experimentally justified assumptions on the injection barriers, the blend morphology, and the kinetics of the charge transfer state involved in geminate and nongeminate recombination. All of these properties are independently calibrated using charge extraction, electron microscopy, and transient absorption measurements, respectively. Clear evidence is provided that the conclusions drawn from microscopic and transient KMC modeling are indeed relevant for real operating organic solar cell devices.Comment: final version; license update

Biochemical composition of red, green and brown seaweeds on the Swedish west coast

Seaweed biomass has the potential to become an important raw material for bio-based production. The aim of this study was to screen the overall composition of several seaweed species on the Swedish west coast, including some scarcely studied species, to provide fundamentals for evaluation of biorefining potential and to benchmark with already potentially industrially relevant species and commercially important land-based biomasses. Twenty-two common seaweed species (green, red, brown) were collected and the carbohydrate, ash, protein, water and metal contents were measured. Carbohydrate content varied between 237 and 557\ua0g\ua0kg−1 dry weight (dw), making it the largest constituent, on a dry weight basis, of most species in the study. Ash, which is considered unwanted in biorefining, ranged between 118 and 419\ua0g\ua0kg−1 dw and was the largest constituent in several seaweeds, which were therefore considered unsuitable for biorefining. Protein content was most abundant in the red seaweeds but was generally low in all species (59–201\ua0g\ua0kg−1 dw). High contents of several unwanted metals for processing or human consumption were found (e.g. aluminium, arsenic, copper, chromium and nickel), which need to be considered when utilizing seaweeds for certain applications. Potential targets for further biorefinery development mostly include species already known for their potential (Saccharina latissima, Laminaria digitata and Chondrus crispus) while some, such as Halidrys siliquosa and Dilsea carnosa, have not been previously noted. However, more detailed studies are required to explore biorefinery processes for these seaweeds, as well as how to potentially cultivate them

How does the skin move on the neck of the horse? : validation of a method for motion analysis of the cervical spine in the horse

Höghastighetsfilmning är en teknik som ofta används inom rörelseforskning på häst, särskilt för att registrera ledrörelse. Reflektoriska hudmarkörer sätts på anatomiska landmärken, vilka sedan filmas med höghastighetskameror. En felkälla med dessa mätningar är att huden förskjuts jämfört med underliggande skelett. Detta fenomen beskrevs första gången i början av 1900-talet och har sedan dess studerats relativt omfattande framför allt för hästens extremiteter men även för ryggen. Däremot har hudförskjutningen på halsen inte studerats tidigare och det var syftet med det här arbetet. Halskotorna på fem hästar markerades med röntgentäta hudmarkörer för att sedan röntgas i olika positioner, normal position, placerad ”i form” med välvd nacke och nosen i lodrätt plan samt med ”nos mot karpus”. Utifrån röntgenbilderna beräknades hudförskjutningen genom att mäta markörernas förflyttning jämfört med kotkroppen. Arbetet begränsades till beskrivning av hudförskjutningen över C5 och C6. Vid positionen ”i form” jämfört med normal position försköts huden generellt i dorsal och kranial riktning och vid positionen ”nos mot karpus” jämfört med normal position försköts huden generellt i ventral och ytterligare kranial riktning. I denna studie fick medelvärdena av hudförskjutningen relativt hög standardavvikelse vilket kan förklaras av det begränsade antalet hästar, att de manuella beräkningarna inte blir exakt korrekt trots noggrannhet samt att en viss lateralflexion eller rotation kan förekomma i bilderna då detta är mycket svårt att skilja från de effekter som olika förstorningseffekter i bilden ger upphov till. Men studien tyder på en hudförskjutning över halsen som var upp till 6-7 cm i vissa fall och hudförskjutningen är ett fenomen som man måste ha i åtanke vid användning av hudmarkörer vid rörelseforskning på halsen på hästar.In motion analysis research in horses, it is common to use skin markers placed on anatomical landmarks that are recorded with high-speed cameras. The information from the studies can then be used to calculate for example joint angles and range of motion. One source of error in these measurements is that the skin is displaced compared to the underlying bone. This phenomenon was first described in the early 1900s, and has since been studied, especially focusing on the horse's limbs, but also on the back. However, the skin displacement of the neck has not been studied before and it was the aim of this study. The cervical vertebrae of five horses were marked with radiopaque skin markers and then xrayed in different positions; normal position, "in shape" with a curved neck and nose in the vertical plane and with the "nose against carpus". Based on the x-ray images skin displacement was calculated by measuring the marker's movements compared to the vertebrae. The study was limited to the description of the skin displacement over C5 and C6. In the position "in shape" compared to the normal position the skin was displaced in dorsal and cranial direction and in the position "nose against carpus" compared to the normal position the skin was displaced in ventral and further cranial direction. In this study, the relatively high standard deviation of the mean values of the skin displacement can be explained by the limited number of horses, the manual calculations that might not be exactly correct and by the fact that a certain amount of lateral flexion or rotation may occur in the photos, as this is very difficult to distinguish from the effects that different magnification effects in the image gives rise to. But the study suggests a skin displacement over the neck of up to 6-7 cm and skin displacement is a phenomenon that must be kept in mind when using skin markers in motion analysis research of the neck of horses